68
Installation and Verification Manual
3
Performance Tests
Internal Reference Clock Accuracy
Specification
Accuracy of Transmitter Internal Clock:
•
Settability
±
0.5 ppm
•
Stability
±
3 ppm over temperature range
•
Ageing
±
1 ppm/year
Description
The test uses a Frequency Counter or DSn Test Set connected to
the appropriate Clock output port. When the Transmitter is set
to Internal Clock the reference output is derived from the
instrument internal 10 MHz reference which is also used in
main signal generation.
An alternative test method using the Frequency Counter is
provided for the DS1 check if a suitable DSn Test Set is not
available. However, in this case it should be noted that as this
signal is a Framed All 1s Ternary signal the expected result on
the Frequency Counter is offset due to the effect of Framing
Bits in the signal.
Clock Output
Frequency
Accuracy
2 MHz
2.048 MHz
±
4.5 ppm
DS1 (BITS Clock)
1.544 MHz
±
4.5 ppm
N O T E
The 2 MHz output is only available when SDH or En rate is selected on the
Transmitter. The DS1 output is only available when SONET or T-Carrier rate
is selected on the Transmitter.
BITS Clock is not a binary format signal. Signal is a Ternary All 1s DS-1
signal with ESF Framing, clocked at 1.544 MHz.
panther3_iv.book Page 68 Wednesday, January 15, 2003 12:03 PM
